title: High serum 25-hydroxyvitamin D levels do not retard postmenopausal bone loss in Japanese women: the Yokogoshi study.
abstract: We conducted a cohort study exploring an association between serum 25-hydroxyvitamin D (serum 25(OH)D) and parathyroid hormone (PTH) levels and 5-year changes in bone mineral density (BMD) in 482 postmenopausal women. High serum 25(OH)D levels do not retard postmenopausal bone loss within the lumbar spine or femoral neck, and high PTH levels potentially increase hip bone loss.
  
  
  OBJECTIVE
  The aim of this study was to explore an association between serum 25(OH)D levels and 5-year changes in BMD in postmenopausal women.
  
  
  METHODS
  This 5-year cohort study included 482 women between 55 and 74 years of age who lived in a community in Japan. Medical examinations were conducted in 2005 and 2010. Data were obtained on baseline serum 25(OH)D and intact parathyroid hormone (iPTH) levels. Outcomes of this study were 5-year changes in BMDs of the lumbar spine and femoral neck. Covariates included years since menopause, body mass index (BMI), lifestyle factors, and weight change. Changes in BMDs among quartiles of serum 25(OH)D were compared with analysis of covariance.
  
  
  RESULTS
  The mean age of subjects was 63.1 years, and mean serum 25(OH)D levels were 56.0 nmol/L. Age and decrease in weight were significantly associated with decreases in BMDs of both the lumbar spine (P for trend < 0.001 and =0.002, respectively) and femoral neck (P for trend = 0.026 and <0.001, respectively); low BMI was associated with a decrease in lumbar spine BMD (P for trend < 0.001). No significant associations were found between serum 25(OH)D levels and changes in BMDs. High serum iPTH levels were associated with a greater decrease in femoral neck BMD (P for trend = 0.026).
  
  
  CONCLUSIONS
  High serum 25(OH)D levels do not retard postmenopausal bone loss within the lumbar spine or femoral neck, and high PTH levels potentially increase hip bone loss.
authors.affiliation: Division of Preventive Medicine, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachi-dori, Chuo-ku, Niigata, 951-8510, Japan, kitam@med.niigata-u.ac.jp.
authors.forename: Kaori
authors.initials: K
authors.lastname: Kitamura
authors.forename: Kazutoshi
authors.initials: K
authors.lastname: Nakamura
authors.forename: Toshiko
authors.initials: T
authors.lastname: Saito
authors.forename: Ryosaku
authors.initials: R
authors.lastname: Kobayashi
authors.forename: Rieko
authors.initials: R
authors.lastname: Oshiki
authors.forename: Tomoko
authors.initials: T
authors.lastname: Nishiwaki
authors.forename: Masanori
authors.initials: M
authors.lastname: Iwasaki
authors.forename: Akihiro
authors.initials: A
authors.lastname: Yoshihara
mesh_terms: D015502:Absorptiometry, Photon; D000368:Aged; D000704:Analysis of Variance; D015519:Bone Density / Q000502:physiology*; D015331:Cohort Studies; D005260:Female; D005272:Femur Neck / Q000502:physiology; D006801:Humans; D008159:Lumbar Vertebrae / Q000502:physiology; D008875:Middle Aged; D015663:Osteoporosis, Postmenopausal / Q000097:blood / Q000503:physiopathology*; D010281:Parathyroid Hormone / Q000378:metabolism*; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000378:metabolism; D015431:Weight Loss / Q000502:physiology
chemical_list: D010281:Parathyroid Hormone; D014807:Vitamin D; C104450:25-hydroxyvitamin D